The Messenger of Allah ﷺ said, "By Allah, this world compared to the Hereafter is like one of you dipping his finger into the sea. Let him see what it brings back."
قال رسول الله ﷺ: والله ما الدنيا في الآخرة إلا مثل ما يجعل أحدكم إصبعه هذه في اليم، فلينظر بم ترجع.
Muslim reported it in the Book of Paradise and the Description of Its Bliss (55:2858) through several routes from Ismail bin Abu Khalid, who said, Qays narrated to us, saying, I heard Mustawrid, and he mentioned it.